What Labour’s manifesto actually said about electoral reform

It’s become a bit of an urban myth in some (Labour) circles that Labour’s 2010 general election manifesto only promised a referendum on the alternative vote, but didn’t say anything about committing Labour MPs or the Labour Party to a yes vote. But that’s not actually what the manifesto said:

To ensure that every MP is supported by the majority of their constituents voting at each election, we will hold a referendum on introducing the Alternative Vote for elections to the House of Commons.

To ensure means not only holding a referendum, but also voting Yes.